Implement optional audio preview when hovering over songs in the Folders view. Features include:
- Toolbar toggle button (off by default) to enable/disable hover preview
- ~0.5s dwell delay to avoid accidental audio playback while scrolling
- Dedicated <audio> element (never touches main player)
- Equalizer indicator animation overlay on song art while playing
- Per-surface localStorage persistence
- Automatic fallback through preview.ogg → stems/full.ogg → stems/audio.mp3
Bump Folder Library from 1.8.0 to 1.9.0. Remove 'auto play on hover' from roadmap as it's now implemented.
Adds the bundled Folder Library plugin (browse the DLC library by its on-disk
folder tree, in-app folder CRUD, drag-and-drop + dialog song moves, sort/filter,
live search), wired into the classic v2 toolbar and the v3 Songs page.
Includes the screen.js IIFE dedup (unified surface factory) and review fixes:
path-traversal guard on /song/move, folder-delete data-loss fix, plural
/api/plugins/<id> namespace, loose-folder song recognition, error-text escaping,
v3 setLibView null-guard, and tests.
Co-authored-by: Kyle <kyle.j.t@live.co.uk>
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
